The present invention relates to a new and improved construction of rolling mill for rolling materials substantially in web form.
Generally speaking, the rolling mill of the present development, which serves to roll web-like materials, is of the type comprising at least one work roll which coacts with a counter roll. Between the work roll and the counter roll there is passed the material which is to be rolled. Additionally, there is provided a support or back-up roll at which there is supported or braced the work or working roll. The support roll is constituted by a controlled deflection roll--also referred to in the art as a roll with bending or sag compensation--which contains a roll shell rotatable about a stationary roll support or beam. The roll shell is supported at the roll support or beam by means of support or pressure elements, the supporting force of which can be controlled individually or in groups.
Such type of rolling mill is known, for instance, from U.S. Pat. No. 4,059,976, granted Nov. 29, 1977. In contrast to conventional roll stands equipped with solid support rolls, the rolling mills of the aforementioned type allow for a particularly good influencing of the rolling operation as concerns the thickness and, in particular, the evenness of a rolled metallic web, for instance, a cold-rolled aluminum foil. These advantages are attributable to the ability to control the contact or pressing force of the support or pressure elements individually or in groups.
With equipment of this type, which is intended for use with extremely high rolling forces, such as, for instance, for the cold-rolling of iron or ferrous materials, it has been found to be disadvantageous that the required supporting forces of the support or pressure elements become extremely irregular, attaining peak values which require unrealistically high pressures of the hydraulic pressurized fluid medium acting upon the support or pressure elements.